Energetika.NET – reliable energy news for SEE – China towards new nuclear energy era with thorium – Author: Jasmina Nikoloska, Valerija Hozjan
In late January, the Chinese National Academy of Sciences announced its initiative to investigate and develop an entirely new nuclear energy programme using thorium as a fuel.
Currently, nuclear stations in China account for only 2 per cent of the country’s total power generation. According to the NDRC’s (National Development and Reform Commission) nuclear and long-term development plan, by 2020, China’s installed capacity of nuclear power will reach 40GWe and by 2050 it may be increased to 260GWe or more. The Chinese National Academy’s ultimate target is to develop a wholly new nuclear system that will be the future of advanced nuclear fission energy – a nuclear energy, thorium-based molten salt reactor system – within about 20 years.
The thorium molten-salt reactor (TMSR), as the Chinese call it, is a fourth-generation nuclear reactor which uses liquid salt as both fuel and coolant, also known as liquid fluoride thorium reactor (LFTR), British news source The Register wrote on 1 February.
Thorium (or uranium-233 produced from it) can be used as fuel in different reactor designs. In USA, for example, thorium was used in the high temperature reactor in Fort St. Vrain, which operated as a commercial nuclear power plant between 1977 to 1989, dr. Igor Jencic from the Jozef Stefan Institute explained for Energetika.NET. There are molten salt reactor designs, which use uranium (plutonium) as fuel; at the same time, some use thorium as fuel. The interlocutor agreed that the current combination of molten salt and thorium fuel was the most promising. He said this was not, however, exclusive Chinese idea. “A molten salt reactor is one of the six possible reactor designs of the 4th generation. Argentina, Brazil, Canada, France, Japan, South Korea, South Africa, Great Britain, USA, Switzerland, Euratom, China and Russia participate in GEN-IV, where these reactors are being developed. The concept researched and the time spent on individual research depends on the country.” Jencic added that research results within the mentioned project were “public in principle”. “Once specific technological solutions are reached, this might change.”
Breakeven conversion ratio
In Kirk Sorensen’s recent blog entry about the announcement of the new nuclear scheme at the Chinese National Academy of Sciences, he explained that the Chinese recognised that a “thorium-fueled MSR is best run with uranium-233 fuel, which inevitably contains impurities (uranium-232 and its decay products) that preclude its use in nuclear weapons. Dr. Jencic added there were many uranium-233 weapons deficiencies (due to the presence of uranium-232) in comparison with plutonium; therefore the Americans had abandoned such military use in the past. “An air engine was being developed which could (because of the small size or large specific power) be operated by a molten salt reactor. This development most likely had military implications, but it was abandoned by the end of the 50ies.”
Operating an MSR on the “pure” fuel cycle of thorium and uranium-233 means that a breakeven conversion ratio can be achieved, and after being started on uranium-233, only thorium is required for indefinite operation and power generation, says Sorensen. He also estimated that between 5000-6000 tons of thorium could produce as much energy as the world currently consumes each year.
Future nuclear technology?
Switching from uranium to thorium as the primarily nuclear fuel was one of the promising energy and climate change solutions proposed two years ago as a part of the Manchester Report. Such could lead to cheaper, safer and more sustainable nuclear power.
Jencic added that probability of certain kinds of accidents did not depend on fuel, but on the design (light water reactor, gas cooled reactor, etc.). “It is true that certain kinds of accidents or technological problems, which are the most dangerous with light water reactors, cannot occur, even in theory, with molten salt reactor; the latter have, however, other problems. Again, problems do not depend on fuel (uranium or thorium).” It is true that radioactive waste that occurs when using thorium as fuel is short-lived in comparison with waste that occurs when uranium is used. Thorium waste decays to the level of natural radioactivity within several hundreds of years.
It is supposed that they have been storing thorium from rare-earth mining for years and if this is true, the Chinese will have hundreds of thousands of years of thorium already mined and available for use, according to Sorensen. The Chinese understood that “we need a better stove that can burn more fuel”, as Xu Hongjie, a researcher on the future of nuclear power at the Shanghai Institute of Applied Physics, said in an interview with Wenhui News.
Although the prospects are promising, scientists say that there are still many difficulties to be overcome. But it is clear that China is becoming self-sufficient in reactor design and construction, as well in other aspects of the fuel cycle.
ENVIRONMENTAL NEWS 